Abstract: The feasibility of diffusion bonding of 1420 Al-Li alloy under certain technical conditions was investigated in this paper.The microstructure,fracture morphology and microhardness of the joints were studied.The results show that the excellent metallurgical bonding can be obtained through the sufficient diffusion of atoms near the joint boundaries by using the reasonable processing parameters.The welded joint with homogenous microstructures can be obtained by using the copper as the interlayer material.When the nickel is used as interlayer material,the intermetallic compounds are formed by diffusion,which can improve the strength of the joints.